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Biomedical subjects

Jianping Wang

Publications and source records attributed to Jianping Wang.

At least 37 records · Page 2Linked to original sources
PubMed2003

Arsenic speciation in the urine and hair of individuals exposed to airborne arsenic through coal-burning in Guizhou, PR China.

The extent of exposure of residents of Changqing (Guizhou, PR China) to arsenic through coal-burning was investigated. Despite the low coal-arsenic content (56.3+/-42.5 mg As kg(-1)) when compared with coals collected at different location and times from the same province, more than 30% of the study subjects have shown symptoms of arsenicosis. Coal, urine, hair, and water samples were collected in mid-September 2001 and analysed for arsenic. The average urinary and hair-arsenic concentrations in the exposed subjects were 71.4+/-37.1 microg As g(-1) creatinine (control 41.6+/-12.1) and 7.99+/-8.16 mg kg(-1), respectively. A positive correlation between the hair and urinary-arsenic concentration (R(2)=0.601) was found. There was no significant difference between females and males for both urinary and hair-arsenic concentrations. Females were found to have a higher dimethylarsinic acid but lower percentages of inorganic arsenic and monomethylarsonic acid in their urine than males.

Adult↗
PubMed2003

A global health problem caused by arsenic from natural sources.

Arsenic is a carcinogen to both humans and animals. Arsenicals have been associated with cancers of the skin, lung, and bladder. Clinical manifestations of chronic arsenic poisoning include non-cancer end point of hyper- and hypo-pigmentation, keratosis, hypertension, cardiovascular diseases and diabetes. Epidemiological evidence indicates that arsenic concentration exceeding 50 microg l(-1) in the drinking water is not public health protective. The current WHO recommended guideline value for arsenic in drinking water is 10 microg l(-1), whereas many developing countries are still having a value of 50 microg l(-1). It has been estimated that tens of millions of people are at risk exposing to excessive levels of arsenic from both contaminated water and arsenic-bearing coal from natural sources. The global health implication and possible intervention strategies were also discussed in this review article.

Arsenic↗
PubMed2003

Dysregulated Sonic hedgehog signaling and medulloblastoma consequent to IFN-alpha-stimulated STAT2-independent production of IFN-gamma in the brain.

The type I IFNs (IFN-alpha and IFN-beta), which are crucial in antiviral defense and immune regulation, signal via the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway with activation of STAT1 and STAT2. Here, the function of STAT2 was studied in transgenic mice (termed GIFN/STAT2-/-) with CNS production of IFN-alpha. Surprisingly, GIFN/STAT2-/-, but not GIFN/STAT1-null, transgenic mice, with CNS production of IFN-alpha, died prematurely with medulloblastoma. An immune response also induced in the brain of the GIFN/STAT2-/- mice was associated with IFN-gamma gene expression by CD3+ T cells and the activation of the STAT1, STAT3, STAT4, and STAT5 molecules. Expression of the Sonic hedgehog (Shh) and the downstream transcriptional factor Gli-1 genes, implicated in the pathogenesis of medulloblastoma, was found to be significantly increased and cotranscribed in cerebellar granule neurons of the GIFN/STAT2-/- mice. IFN-gamma, but not IFN-alpha, induced STAT1-dependent expression of the Shh gene in cultured cerebellar granule neurons. Thus, there is an unexpected and extraordinarily adverse biological potency of IFN-alpha in the CNS when the primary signal transduction molecule STAT2 is absent. Moreover, a hitherto unknown role is indicated for the immune system in the pathogenesis of developmental disorders and tumorigenesis of the CNS via dysregulated Shh signaling mediated by IFN-gamma.

Animals↗
PubMed2003

[An artificial neural network model for lake color inversion using TM imagery].

The technology of artificial neural network was used for inversing water quality parameters from TM imagery data in the paper in order to study water quality and eutrophic status of lake. On the basis of satellite synchronous monitoring experiment, a BP neural network model was constructed, in which concentrations of SS, CODMn, DO, T-N, T-P and chlo-a were inversed from Landsat TM data and the accuracy of which was good, the relative error of which could be controlled below 25%. Moreover, the reasons of simulating error, ways of improving model and applications of the model were also analyzed in detail. The results of this research told that based on a small-scale of satellite synchronous experiment, the model could be applied successfully in investigation, analysis and estimation of lake water quality.

Color↗
PubMed2003

Pathological demography of native patients in a nephrology center in China.

OBJECTIVE: To analysis the pathological demography in Chinese patients undergoing renal biopsy from our nephrology center. METHODS: Between January 1979 and October 2000 in Jinling Hospital, Nanjing, China, 10,002 attempts of percutaneous renal were performed in patients with renal disease from 33 provinces of China. The pathological classifications were made according to the WHO criteria of 1982 for renal pathology or the modified WHO criteria of 1995 by a panel of pathologists and nephrologists during routine clinical-pathological rounds. The pathological demography between those specimens collected from 1979 - 1989 and those from 1990 - 1999 was compared. RESULTS: The mean age of the 10,002 subjects undergoing renal biopsy was 31.4 +/- 13.0 years (ranging from 1 to 78 years), with a male to female ratio of 1.3:1; for the 592 renal transplant recipients, the mean age was 37.5 +/- 9.1 years (ranging from 16 to 66 years), with a male to female ratio of 2.36:1. Primary glomerular diseases (PGD) accounted for 71% of the total patients undergoing renal biopsies, secondary glomerular nephritis (SGN) 23%, tubular-interstitial diseases 3.2%, unclassified renal diseases 1.3%, hereditary and congenital renal diseases 1.0%, end stage renal diseases 0.96%, and recently realized or rare renal diseases 0.15%. IgA nephropathy (IgAN) was the most frequent pathological pattern (40%) of PGD, followed by mesangial proliferative lesion (MsPL) (30%), membranous nephropathy (MN) (10%), and focal segmental glomerulosclerosis (FSGS) (6%). Lupus nephritis (LN) was the most pathology common seen (74%) in SGN. During the 22 years of the study period, there was a steady increase in patients with SGN discovered during pathological evaluation of renal disorders. A rise in prevalence was found in IgA nephropathy, MN (both P < 0.001), crescentic glomerulonephritis (P < 0.0001), anti-GBM disease, and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura related renal damages (both P < 0.001). There was a decrease in endocapillary proliferative glomerulonephritis (P < 0.001) and IgM nephropathy (IgMN) (P < 0.01) from 1990 - 1999 as compared to 1979 - 1989. Infrequent renal pathological entities were also diagnosed in this group, including Niemann Pick disease, Fabry's disease, POEMS syndrome, and lipoprotein glomerulonephropathy. CONCLUSIONS: This is the largest series of renal biopsy data in China, and therefore may reflect the demographic picture of renal diseases in this country. Changes in prevalence of renal pathological entities were reflected in this group of patients over the last 22 years. In primary glomerular diseases, IgA nephropathy is still the most frequently observed pathological pattern. In SGN, LN appeared the most often. Increased prevalence was found in anti-GBM nephritis and HUS/TTP.

Adolescent↗
PubMed2002

STAT1 deficiency unexpectedly and markedly exacerbates the pathophysiological actions of IFN-alpha in the central nervous system.

Although signal transducer and activator of transcription 1 (STAT1) is an essential signaling molecule in many IFN-alpha-regulated processes, some biological responses to IFN-alpha can occur independently of STAT1. To establish the role of STAT1 in mediating the biological actions of IFN-alpha in the CNS, transgenic mice [termed glial fibrillary acidic protein (GFAP)-IFN-alpha] with astrocyte production of IFN-alpha were bred to be null for the STAT1 gene. Surprisingly, GFAP-IFN-alpha mice deficient for STAT1 developed earlier onset and more severe neurological disease with increased lethality compared with GFAP-IFN-alpha mice sufficient for STAT1. Whereas the brain of 2- to 3-month-old GFAP-IFN-alpha mice showed little, if any abnormality, the brain from GFAP-IFN-alpha mice deficient for STAT1 had severe neurodegeneration, inflammation, calcification with increased apoptosis, and glial activation. However, the cerebral expression of a number of IFN-regulated STAT1-dependent genes increased in GFAP-IFN-alpha mice but was reduced markedly in GFAP-IFN-alpha STAT1-null mice. Of many other signaling molecules examined, STAT3 alone was activated significantly in the brain of GFAP-IFN-alpha STAT1-null mice. Thus, in the absence of STAT1, alternative signaling pathways mediate pathophysiological actions of IFN-alpha in the living brain, giving rise to severe encephalopathy. Finally, STAT1 or a downstream component of the JAKSTAT pathway may protect against such IFN-alpha-mediated injury in the CNS.

Animals↗
PubMed2002

[Acquired mutation of type II transforming growth factor-beta receptor gene in glomerulosclerosis].

OBJECTIVE: To investigate the acquired mutation of type II transforming growth factor beta receptor TbetaR II gene plays a role in the process of glumerulosclerosis. METHODS: Biopsy specimens of 32 patients with primary focal segmental glomerulosclerosis (FSGS) were examined. Microdissection was used to isolate the morphologically normal glumeruli, segmental sclerotic glomeruli (SSG) global sclerotic glomeruli (GSG), and in the same specimen, representing the sequence of glomerulosclerosis. DNA was extracted by one-step method. The A10 microsatellite instability (709 approximately 718) in TbetaRII gene was detected by high-fidelity PCR and strand length polymorphism. Scanning technique was used to calculate the mutation rate of TBRII gene A10 sequence. RESULTS: A total of 192 sites of glomeruli from 32 patients were analyzed. The standard curve for mutant integrated pixel density (IPD) percentages (10% 32% 55% 75% 88%) versus DNA mutant ratios (17% 24% 53% 79% 95%) showed excellent linear correlation (r = 0.990 8). DNA from the glomeruli of NG, SSG, and GSG of all cases showed very low ratios of mutant allele (1 approximately 5%). CONCLUSION: Mutation of TbetaRII gene A10 microsatellite sequence can not been detected during the progress of glomerulosclerosis.

Adolescent↗
PubMed2002

Understanding soluble arsenate removal kinetics by zerovalent iron media.

Zerovalent iron filings have been proposed as a filter medium for removing arsenic compounds from potable water supplies. This research investigated the kinetics of arsenate removal from aqueous solutions by zerovalent iron media. Batch experiments were performed to determine the effect of the iron corrosion rate on the rate of As(V) removal. Tafel analyses were used to determine the effect of the As(V) concentration on the rate of iron corrosion in anaerobic solutions. As(V) removal in column reactors packed with iron filings was measured over a 1-year period of continuous operation. Comparison of As(V) removal by freely corroding and cathodically protected iron showed that rates of arsenate removal were dependent on the continuous generation of iron oxide adsorption sites. In addition to adsorption site availability, rates of arsenate removal were also limited by mass transfer associated with As(V) diffusion through iron corrosion products. Steady-state removal rates in the column reactor were up to 10 times faster between the inlet-end and the first sampling port than between the first sampling port and the effluent-end of the column. Faster removal near the influent-end of the column was due to a faster rate of iron oxidation in that region. The presence of 100 microg/L As(V) decreased the iron corrosion rate by up to a factor of 5 compared to a blank electrolyte solution. However, increasing the As(V) concentration from 100 to 20,000 microg/L resulted in no further decrease in the iron corrosion rate. The kinetics of arsenate removal ranged between zeroth- and first-order with respect to the aqueous As(V) concentration. The apparent reaction order was dependent on the availability of adsorption sites and on the aqueous As(V) concentration. X-ray absorption spectroscopy analyses showed the presence of iron metal, magnetite (Fe3O4), an Fe(III) oxide phase, and possibly an Fe(II,III) hydroxide phase in the reacted iron filings. These mixed valent oxide phases are not passivating and permit sustained iron corrosion and continuous generation of new sites for As(V) adsorption.

Adsorption↗
PubMed2002

New approach for enlargement of medical electronic endoscopic images.

To compensate for the imperfections of the endoscopic mechanical structure and the limitations of working space, a new technology based on the recursive minimum/maximum method is proposed to enlarge images obtained by the medical electronic endoscope. This method can be used repeatedly to obtain image enlargement to 2x by optimizing the neighborhood information of the pixels of interest in adjustable windows. In order to ensure the best evaluation of the pixel, the algorithm criterion is presented to decide whether the new gray value is assigned to the pixel. Experimental results from enlarged endoscopic images are presented that demonstrate that the recursive minimum/maximum method for image enlargement can preserve the fine details with rich edge information and with better visualization.

Algorithms↗
PubMed2002

Cytokine signaling in the brain: putting a SOCS in it?

A new family of cytokine-inducible proteins, termed "suppressors of cytokine signaling" (SOCS), was discovered recently; these proteins function as negative regulators of signaling pathways involved in the cellular actions of many cytokines, growth factors, and hormones. Gene manipulation studies in mice point to the central importance of individual SOCS proteins in maintaining homeostasis by limiting cellular responses to specific cytokines or growth factors in a variety of different physiological systems. Cytokines modulate a wide variety of biological responses in the CNS, so members of the SOCS family might play crucial roles in regulating intracellular signaling by these effectors in both normal and disease states. Although to date studies of the neurobiology of the SOCS family have been limited, we know that many SOCS genes are constitutively expressed in the developing and adult brain, whereas the expression of others, particularly the SOCS1 and SOCS3 genes, can be highly regulated. Furthermore, roles for the SOCS are now evident in the modulation of neuroimmunoendocrine functions affected by a variety of cytokines, including leptin and members of the growth hormone and the interleukin-6/gp130 superfamilies. Overall, these findings point to the SOCS as likely crucial negative modulators in the temporal and spatial regulation and intensity of cytokine signaling and therefore actions in the CNS.

Animals↗
PubMed2002

Comparison of the dynamics of the primary events of bacteriorhodopsin in its trimeric and monomeric states.

In this paper, femtosecond pump-probe spectroscopy in the visible region of the spectrum has been used to examine the ultrafast dynamics of the retinal excited state in both the native trimeric state and the monomeric state of bacteriorhodopsin (bR). It is found that the excited state lifetime (probed at 490 nm) increases only slightly upon the monomerization of bR. No significant kinetic difference is observed in the recovery process of the bR ground state probed at 570 nm nor in the fluorescent state observed at 850 nm. However, an increase in the relative amplitude of the slow component of bR excited state decay is observed in the monomer, which is due to the increase in the concentration of the 13-cis retinal isomer in the ground state of the light-adapted bR monomer. Our data indicate that when the protein packing around the retinal is changed upon bR monomerization, there is only a subtle change in the retinal potential surface, which is dependent on the charge distribution and the dipoles within the retinal-binding cavity. In addition, our results show that 40% of the excited state bR molecules return to the ground state on three different time scales: one-half-picosecond component during the relaxation of the excited state and the formation of the J intermediate, a 3-ps component as the J changes to the K intermediate where retinal photoisomerization occurs, and a subnanosecond component during the photocycle.

Bacteriorhodopsins↗
PubMed2002

Time-resolved long-lived infrared emission from bacteriorhodopsin during its photocycle.

The infrared emission observed below 2000 cm(-1) upon exciting retinal in bacteriorhodopsin (bR) is found to have a rise time in the submicrosecond time regime and to relax with two exponential components on the submillisecond to millisecond time scale. These time scales, together with the assignment of this emission to hot vibrations from the all-trans retinal (in bR) and the 13-cis retinal (in the K intermediate), support the recent assignment of the J-intermediate as an electronically excited species (Atkinson et al., J. Phys. Chem. A. 104:4130-4139, 2000) rather than a vibrationally hot K intermediate. A discussion of these time scales of the observed infrared emission is given in terms of the competition between radiative and nonradiative relaxation processes of the vibrational states involved.

Bacteriorhodopsins↗
PubMed2002

Fourier transform infrared study of the effect of different cations on bacteriorhodopsin protein thermal stability.

The effect of divalent ion binding to deionized bacteriorhodopsin (dI-bR) on the thermal transitions of the protein secondary structure have been studied by using temperature-dependent Fourier transform infrared (FT-IR) spectroscopy. The native metal ions in bR, Ca(2+), and Mg(2+), which we studied previously, are compared with Mn(2+), Hg(2+), and a large, synthesized divalent organic cation, ((Et)(3)N)(2)Bu(2+). It was found that in all cases of ion regeneration, there is a pre-melting, reversible conformational transition in which the amide frequency shifts from 1665 to 1652 cm(-1). This always occurs at approximately 80 degrees C, independent of which cation is used for the regeneration. The irreversible thermal transition (melting), monitored by the appearance of the band at 1623 cm(-1), is found to occur at a lower temperature than that for the native bR but higher than that for acid blue bR in all cases. However, the temperature for this transition is dependent on the identity of the cation. Furthermore, it is shown that the mechanism of melting of the organic cation regenerated bR is different than for the metal cations, suggesting a difference in the type of binding to the protein (either to different sites or different binding to the same site). These results are used to propose specific direct binding mechanisms of the ions to the protein of deionized bR.

Bacteriorhodopsins↗
PubMed2002

The effect of FasL expression on pancreatic islet allografts.

OBJECTIVE: To investigate the immune privilege induced by the Fas ligand (FasL) expressed by cotransplanted testicular Sertoli cells in islet allografts, and the effect of FasL gene transfection on islet cells in pancreatic islet allografts. METHODS: Allogeneic islets and testicular cells were cotransplanted into diabetic recipients. Pancreatic islets were infected with the recombinant adenovirus, AdV-FasL, and transplanted into diabetic recipients. Allograft survival, islet function, apoptosis of infiltrative lymphocytes in allografts and gene transfected islet allografts were analyzed. RESULTS: All animals receiving islet allograft alone returned to a diabetic state in a few days (mean survival time 6.3 +/- 0.6 days). When the quantity of testicular cells cotransplanted with islets increased to 1 x 10(7), all animals remained normoglycemic throughout the follow-up period (60 days). FasL expression by cotransplanted Sertoli cells induced apoptosis of activated lymphocytes. Rejection of allografts in the FasL gene transfer group was accelerated and allograft survival was shortened to 3.4 +/- 0.2 days (P < 0.05). Pancreatic islets infected with AdV-FasL demonstrated positive staining for FasL at 24h after transplantation, with increased intensity at 48h. Apoptosis assays of pancreatic islet allografts at 24h and 48h revealed apoptosis of transfected islets. CONCLUSIONS: FasL-expressing testicular Sertoli cells can induce apoptosis of activated lymphocytes. Cotransplantation of testicular cells allows long-term survival of allogeneic islets because of immune privilege, but the direct expression of FasL on islet allografts infected with AdV-FasL accelerates islet rejection via islet apoptosis and granulocyte infiltration.

Animals↗
PubMed2002

Glomerular chemokine expression and the effect of steroid and cyclophosphamide pulse therapy in human crescentic glomerulonephritis.

OBJECTIVE: To study glomerular expression of C-C chemokines, monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1alpha and beta (MIP-1alpha, MIP-1beta) and the effect of steroid and cyclophosphamide (CTX) intermittent intravenous pulse therapy on expression in patients with crescentic glomerulonephritis (CGN) to further investigate the underlying mechanism of the treatment. METHODS: Twelve patients with initial biopsy-proven CGN(2), 6 with lupus nephritis (lupus-CGN, LN-CGN) and 6 with vasculitis, (vasculitis-CGN, V-CGN) were enrolled in this study. They underwent an initial biopsy before steroid and CTX intermittent intravenous pulse therapy and were biopsied again one to three months later. Expression of MCP-1, MIP-1alpha, MIP-1beta, and CD68 in glomeruli with cellular and fibrocellular crescents were examined by immunohistochemical analysis in serial sections of renal biopsies. The effect of the pulse therapy on histopathological changes was also observed. RESULTS: Although steroid and CTX intermittent intravenous pulse therapy markedly reduced the degree of glomerular crescent formation both in LN-CGN and V-CGN, the effect of the therapy on glomerular chemokine expression was significantly different between LN-CGN and V-CGN. It was found that steroid and CTX intermittent intravenous pulse therapy reduced the expression of CD68, MCP-1, and MIP-1alpha, but had no effect on MIP-1beta in glomeruli with cellular crescents of patients with LN-CGN. In patients with V-CGN, the therapy also reduced the expression of CD68, but had no effect on MCP-1, MIP-1alpha, and MIP-1beta in glomeruli with cellular crescents. It was noted that the degree of glomerulosclerosis and tubular interstitial fibrosis increased more significantly at the second biopsy in V-CGN as compared to LN-CGN. CONCLUSIONS: The efficacy of steroid and CTX intermittent intravenous pulse therapy in CGN might be affected by reduction of glomerular chemokine expression. The different changes in glomerular expression of MCP-1 and MIP-1alpha in patients with LN-CGN and V-CGN after pulse therapy may correlate to different responses to treatment and prognosis.

Adolescent↗
PubMed2002

[Comparison of colonic J-pouch and straight coloanal anastomosis after low anterior resection for rectal carcinoma: a meta-analysis of 8 randomized trails].

OBJECTIVE: To evaluate the effect of colonic J-pouch coloanal anastomosis after low anterior resection for mid or low rectal cancer on improving defecation and anorectal physiology. METHODS: To make a meta-analysis, prospective randomized controlled trial of with or without colonic J-pouch after low anterior resection for mid or low rectal cancer was conducted. The key words included rectal cancer, J-pouch (or J-pouch) and those randomized from selected reports. The data on bowel function and physiological function of the anal canal and (neo) rectum were meta-analyzed using fixed effect model and random effect model. RESULTS: Eight randomized trails including 378 patients entered this study. After one year follow-up, the functional results showed that there were significant differences in stool frequency per day, urgency and use of medication between colonic J-pouch group and straight coloanal anastomosis group. On physiological function of the anal canal and (neo) rectum, there was significant difference only in rectal compliance between the two groups. But there was no significant difference in other 4 items. CONCLUSIONS: The functional improvement gained from colonic J-pouch coloanal anastomosis continues to benefit the patient with mid or low rectal cancer for at least 12 months. It is necessary to further study about the effect of colonic J-pouch coloanal anastomosis on physiological function of the anal canal and (neo) rectum.

Adult↗